U.S. patent application number 14/562458 was filed with the patent office on 2016-01-07 for oil pump for engine.
This patent application is currently assigned to HYUNDAI MOTOR COMPANY. The applicant listed for this patent is HYUNDAI MOTOR COMPANY, Kia Motors Corporation, MYUNG HWA IND. CO., LTD.. Invention is credited to Hyuk In KWON, Min Kyu OH, Dong Jun YU.
Application Number | 20160003240 14/562458 |
Document ID | / |
Family ID | 54247569 |
Filed Date | 2016-01-07 |
United States Patent
Application |
20160003240 |
Kind Code |
A1 |
YU; Dong Jun ; et
al. |
January 7, 2016 |
OIL PUMP FOR ENGINE
Abstract
An oil pump includes a pump housing comprising an oil input port
formed at one side of the pump housing. An oil output port is
formed at another side of the pump housing. An oil flow unit is
provided at a center of the pump housing, and the oil flow unit
compresses and discharges oil input from the oil input port toward
the oil output port. A bypass passage circulates the oil from the
oil output port to the oil input port. A pressure control chamber
allows the oil to flow through the oil output port and the bypass
passage. The pressure control chamber has a plunger that is
supported by an elastic body and moves in accordance with oil
pressure. A bypass hole is formed at one side of the pressure
control chamber and allows the oil passing through the oil output
port to flow to the bypass passage when the plunger moves due to
the oil pressure. The amount of oil flow increases depending on a
movement distance of the plunger.
Inventors: |
YU; Dong Jun; (Gunpo-si,
KR) ; OH; Min Kyu; (Anyang-si, KR) ; KWON;
Hyuk In; (Incheon, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HYUNDAI MOTOR COMPANY
Kia Motors Corporation
MYUNG HWA IND. CO., LTD. |
Seoul
Seoul
Seoul |
|
KR
KR
KR |
|
|
Assignee: |
HYUNDAI MOTOR COMPANY
MYUNG HWA IND. CO., LTD.
Kia Motors Corporation
|
Family ID: |
54247569 |
Appl. No.: |
14/562458 |
Filed: |
December 5, 2014 |
Current U.S.
Class: |
418/206.1 |
Current CPC
Class: |
F01M 1/02 20130101; F04C
14/26 20130101; F01M 2001/0238 20130101; F01M 1/16 20130101; F04C
29/025 20130101; F04C 15/06 20130101; F04C 2/102 20130101 |
International
Class: |
F04C 2/10 20060101
F04C002/10; F01M 1/02 20060101 F01M001/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 1, 2014 |
KR |
10-2014-0082010 |
Claims
1. An oil pump, comprising: a pump housing including: an oil input
port formed at one side of the pump housing; an oil output port
formed at another side of the pump housing; and an oil flow unit
provided at a center of the pump housing, wherein the oil flow unit
compresses and discharges oil input from the oil input port toward
the oil output port; a bypass passage for circulating the oil from
the oil output port to the oil input port; a pressure control
chamber for allowing the oil to flow through the oil output port
and the bypass passage, wherein the pressure control chamber has a
plunger that is supported by an elastic body and moves in
accordance with oil pressure; and a bypass hole formed at one side
of the pressure control chamber and allows the oil passing through
the oil output port to flow to the bypass passage when the plunger
moves due to the oil pressure, wherein the amount of oil flow
increases depending on a movement distance of the plunger.
2. The oil pump of claim 1, wherein the bypass hole has a width
that gradually increases toward a direction to which the plunger is
pressed-in by the oil pressure.
3. The oil pump of claim 1, wherein a section of the bypass hole
has a shape that is tapered toward a pressed-in direction of the
plunger so that a width of the bypass hole increases toward the
pressed-in direction.
4. The oil pump of claim 1, wherein the pressure control chamber
further includes a drain hole formed on a side thereof, wherein the
drain hole is disposed on a lower part of the plunger relative to
the bypass hole, and spaced apart at a constant interval from the
bypass hole such that the oil filled in the lower part of the
plunger flows to the bypass passage.
5. The oil pump of claim 4, wherein the bypass passage comprises a
baffle extending upwardly along one side of the drain hole formed
in the pressure control chamber.
6. The oil pump of claim 5, wherein the baffle extends upwardly
along the one side of the drain hole formed in the pressure control
chamber on the bypass passage to form a filling flow passage
together with an inner wall of the pump housing.
7. The oil pump of claim 6, wherein the drain hole is disposed at a
lowest portion of the filling flow passage.
8. The oil pump of claim 4, wherein the oil filled in the lower
part of the plunger serves as a damper for dampening the plunger.
Description
CROSS-REFERENCE(S) TO RELATED APPLICATION
[0001] The present application claims the benefit of priority to
Korean Patent Application No. 10-2014-0082010, filed on Jul. 1,
2014, the entire contents of which is incorporated herein for all
purposes by this reference.
TECHNICAL FIELD
[0002] The present disclosure relates to an oil pump for an engine,
and more particularly, to an oil pump for an engine through which
noise generation caused from pressure variation due to movement of
an excessively large amount of oil flow, and vibration generation
and noise caused by resonance generation of the relief valve are
reduced.
BACKGROUND
[0003] Generally, an oil pump of an internal combustion engine
circulates engine oil under pressure to engine components, such as
rotating bearings, sliding pistons, camshaft, and the like to
reduce friction between the components while the engine is running,
thereby providing smooth engine operation.
[0004] Recently, technology for reducing friction between engine
components and improving fuel efficiency has been developed, while
the engine is running using a low friction mechanism such as
continuously variable valve timing (CVVT) and continuously variable
lift (CVVL).
[0005] In particular, a directly-connected type engine oil pump in
which an oil pump of an internal combustion engine is directly
connected to a crankshaft has been used to reduce friction, and
thus improve fuel efficiency and reduce cost in comparison to an
indirectly connected engine oil pump that is driven by a chain
connected to a crankshaft.
[0006] In a conventional oil pump, as shown in FIG. 1, an inner
rotor 5 and an outer rotor 7 are provided at a center of a pump
housing 10 where an intake port 1 and a discharging port 3 are
provided. The oil within an oil fan is drawn into the pump housing
by negative pressure caused by a volume change when the inner rotor
5 and the outer rotor 7 rotate. The oil that is drawn in is
compressed to a high pressure and then discharged to the
discharging port due to a volume change, and then provided to
engine components.
[0007] The oil pressure in the oil pump of the engine, which is
discharged, increases in proportion to the number of engine
reciprocation. When the oil pressure increases excessively
durability of the engine components may be degraded. A relief valve
9 is provided on the oil pump to prevent this excessive increase of
the oil pressure, and the oil is bypassed when the relief valve 9
is opened in accordance with the oil pressure.
[0008] In the related art, an excessively large amount of oil flow
is bypassed instantly due to the excessive oil pressure when the
relief valve 9 operates, and thus, the discharge pressure of the
oil increases to induce resonance of the relief valve.
[0009] In addition, the oil within the engine oil pump may leak
when the oil pump is not operated for a long time, thus generating
resonance in the relief valve when it initially starts.
[0010] The description provided above as a related art of the
present disclosure is just for helping in understanding the
background of the present disclosure and should not be construed as
being included in the related art known by those skilled in the
art.
SUMMARY
[0011] The present disclosure has been made in an effort to solve
the above problems, and an aspect of the present inventive concept
provides an oil pump for an internal combustion engine, through
which noise generation is prevented, caused by pressure variation
due to movement of an excessively large amount of oil flow when a
relief valve is operated. Vibration and noise generation caused by
resonance generation of the relief valve at an initial starting-on
stage is reduced.
[0012] According to an exemplary embodiment of the present
inventive concept, an oil pump is provided comprising a pump
housing including an oil input port formed at one side of the pump
housing, and an oil output port formed at another side of the pump
housing. An oil flow unit for compressing and discharging oil input
from the oil input port toward the oil output port is provided at a
center of the pump housing. A bypass passage circulates oil from
the oil output port to the oil input port. A pressure control
chamber allows the oil to flow through the oil output port and the
bypass passage, wherein the oil pressure control chamber has a
plunger that is supported by an elastic body and moves in
accordance with oil pressure. A bypass hole is formed at one side
of the pressure control chamber and allows the oil passing through
the oil output port to flow to the bypass passage when the plunger
moves due to the oil pressure. The amount of oil flow increases
depending on a movement distance of the plunger.
[0013] The bypass hole may have a width that gradually increases
toward a direction to which the plunger is pressed-in by the oil
pressure.
[0014] A section of the bypass hole may have a shape that is
tapered toward the pressed-in direction of the plunger so that a
width of the bypass hole gradually increases toward the pressed-in
direction.
[0015] The pressure control chamber may further include a drain
hole on a side of the pressure control chamber. The drain hole is
disposed on a lower part of the plunger relative to the bypass hole
and spaced apart each at a constant interval from the bypass hole
such that the oil filled in the lower part of the plunger flows to
the bypass passage.
[0016] A baffle may extend upwardly toward the bypass hole at one
side of the drain hole which is formed in the pressure control
chamber on the bypass passage.
[0017] The baffle may extend upward and away from the one side of
the drain hole which is formed in the pressure control chamber on
the bypass passage to form a filling flow passage together with an
inner wall of the pump housing.
[0018] The drain hole may be disposed at a lowest side of the
filling flow passage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The above and other features of the present inventive
concept will now be described in detail with reference to exemplary
embodiments thereof by illustrating the accompanying drawings which
are given herein below by way of illustration only, and thus are
not limitative of the present disclosure.
[0020] FIG. 1 is a view illustrating schematically a conventional
oil pump of an internal combustion engine.
[0021] FIG. 2 is a view illustrating schematically an oil pump of
an internal combustion engine according to an embodiment of the
present inventive concept.
[0022] FIG. 3 is a view illustrating a baffle at sides of a bypass
hole and a drain hole of the oil pump of an engine shown in FIG.
2.
[0023] FIG. 4 is a view illustrating a pressure control chamber of
the oil pump of an engine shown in FIG. 2.
[0024] FIG. 5 is a view showing differences in generations of noise
and pressure between a conventional oil pump of an engine and an
oil pump of an engine of the present inventive concept.
[0025] It should be understood that the appended drawings are not
necessarily to scale, presenting a somewhat simplified
representation of various exemplary features of the present
inventive concept as disclosed herein, including, for example,
specific dimensions, orientations, locations, and shapes will be
determined in part by the particular intended application and use
environment.
[0026] In the figures, reference numbers refer to the same or
equivalent parts of the present disclosure throughout the several
figures of the drawing.
DETAILED DESCRIPTION
[0027] Hereinafter reference will now be made in detail to various
embodiments of the present inventive concept, examples of which are
illustrated in the accompanying drawings and described below. While
the disclosure will be described in conjunction with exemplary
embodiments, it will be understood that the present description is
not intended to limit the invention to those exemplary embodiments.
On the contrary, the inventive concept is intended to cover the
exemplary embodiments as well as various alternatives,
modifications, equivalents, and other embodiments; which may be
included within the spirit and scope of the invention as defined by
the appended claims.
[0028] It is understood that the term "vehicle" or "vehicular" or
other similar term as used herein is inclusive of motor vehicles in
general, such as passenger automobiles including: sports utility
vehicles (SUV), buses, trucks; and various commercial vehicles;
watercraft including: a variety of boats and ships; aircraft and
the like; and includes hybrid vehicles, electric vehicles, plug-in
hybrid electric vehicles, hydrogen-powered vehicles, and other
alternative fuel vehicles (e.g. fuels derived from resources other
than petroleum). As referred to herein, a hybrid vehicle is a
vehicle that has two or more sources of power, for example, both
gasoline-powered and electric-powered vehicles.
[0029] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the disclosure. As used herein, the singular forms "a," "an," and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise. It will be further understood
that the terms "comprises" and/or "comprising" when used in this
specification, specify the presence of stated features, integers,
steps, operations, elements, and/or components, but do not preclude
the presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof. As
used herein, the term "and/or" includes any and all combinations of
one or more of the associated listed items.
[0030] Hereinafter, an oil pump of an engine according to the
preferred embodiment of the present invention will be described
with reference to the accompanying drawings.
[0031] FIG. 2 is a view illustrating schematically an oil pump of
an engine according to an embodiment of the present inventive
concept; FIG. 3 is a view illustrating a baffle at sides of a
bypass hole and a drain hole of the oil pump of an engine as shown
in FIG. 2; FIG. 4 is a view illustrating a pressure control chamber
of the oil pump of an engine as shown in FIG. 2; and FIG. 5 is a
view showing differences in generations of noise and pressure
between a conventional oil pump of an engine and an oil pump of an
engine of the present inventive concept.
[0032] An oil pump of an engine according to an embodiment of the
present disclosure may include a pump housing 100 at one side of
which an oil input port 102 is formed and at another side of which
an oil output port 104 is formed. An oil flow unit 120 for
compressing and outputting oil input from the oil input port 102
toward the oil output port 104 is provided at a center of the pump
housing 100. A bypass passage 140 is formed to circulate the oil
from the oil output port 104 to the oil input port 102. A pressure
control chamber 160 is provided to flow the oil through the oil
output port 104 and the bypass passage 140. A plunger 162 that is
supported by an elastic body 164 and moves in accordance with oil
pressure is provided in the pressure control chamber 160. A bypass
hole 166 is formed at one side of the pressure control chamber 160
and allows the oil passing through the oil output port 104 to flow
to the bypass passage 140 when the plunger 162 moves due to the oil
pressure. The amount of oil flow increases depending on the
movement distance of the plunger 162.
[0033] As shown in FIG. 2, the oil output port 104 through which
oil is discharged is formed diagonally with respect to the oil
input port 102 through which the oil is input from an oil fan (not
indicated) in the pump housing 100. Further, the oil flow unit 120
is provided at the center of the pump housing 100 to compress the
oil flowing in the pump housing 100, thereby to increase the oil
pressure and then to discharge the oil to the oil output port 104.
Here, the oil flow unit 120 has an inner rotor and an outer rotor
(not shown) for discharging the oil by volume change thereof,
wherein the detailed configurations of an oil pump for outputting
lubricant oil are disclosed variously through prior documents, and
thus, descriptions thereof are omitted.
[0034] The bypass passage 140 is formed in the pump housing 100
such that the oil circulates from the oil output port 104 to the
oil input port 102. Here, the pressure control chamber 160 is
disposed between the oil output port 104 and the bypass passage
140, and the plunger 162 and the elastic body 164 in the pressure
control chamber 160 move by the oil pressure.
[0035] When the plunger 162 moves by the oil pressure as described
above, the bypass hole 166 formed on one side of the pressure
control chamber 160 is opened so that the oil passing through the
oil output port 104 flows to the bypass passage 140 thereby to
control pressure of oil that is discharged.
[0036] According to an embodiment of the present inventive concept,
the bypass hole 166 is formed such that the oil passing through the
oil output port 104 flows to the bypass passage 140, and at the
same time, the amount of oil flow increases in accordance with the
movement distance of the plunger 162.
[0037] That is, when pressure at a side of the oil output port 104
increases to a set pressure, the plunger 162 moves downwardly. When
the plunger moves downwards, according to related art, the amount
of oil flow is bypassed instantly and excessively, and thus, the
variation of oil discharging pressure is increased, thereby
generating noise and vibration.
[0038] However, according to an embodiment of the present inventive
concept, when the plunger 162 moves downwardly, the amount of oil
flow that is bypassed is small at an initial stage, and when the
movement distance of the plunger 162 becomes greater as pressure of
the discharging oil passing through the oil output port 104
increases, the amount of oil flow that is bypassed increases,
thereby resolving sudden pressure variation and reducing noise and
vibration.
[0039] In more detail, the bypass hole 166 has a shape in which a
width thereof gradually increases toward a direction to which the
plunger 162 is pressed-in by the oil pressure. That is, a section
of the bypass hole 166 is tapered toward the pressed-in direction
of the plunger 162 so that the width of the bypass hole 166
gradually increases in the downward direction.
[0040] As a result, when the movement distance of the plunger 162
gradually increases as the pressure of the discharging oil passing
through the oil output port 104 increases, the bypass hole 166 is
gradually opened, such that the width thereof gradually increases
in the downward direction so that the amount of oil flow increases
in accordance with the movement distance of the plunger 162.
[0041] As described above, the bypass hole 166 is formed such that
the amount of oil flow that is bypassed gradually increases as the
movement distance of the plunger 162 increases, thus sudden
excessive pressure variation of oil due to sudden flow of oil is
prevented, when controlling the pressure of the oil that is
discharged, thereby improving noise, vibration and hardness (NVH)
performance.
[0042] A drain hole 168 may be formed on a side of the pressure
control chamber 160, which is disposed on a lower part of the
plunger 162 and spaced at a constant interval from the bypass hole
166, such that the oil filled in a lower part of the plunger 162
flows to the bypass passage 140.
[0043] That is, the plunger 162 is elastically supported by the
elastic body 164 in the pressure control chamber 160 and moves
downwardly when the pressure of oil passing through the oil output
port 104 reaches to a set pressure. Here, the oil flows not only to
the elastic body 164 and but also to a gap between an internal
surface of the pressure control chamber 160 and the plunger 162 to
be filled in the lower part of the plunger 162.
[0044] As described above, in a case where the oil filled in the
lower part of the plunger 162 is not discharged, even though the
oil pressure at a side of the oil output port 104 reaches a set
pressure, the plunger 162 does not move downward due to the oil in
the lower part of the plunger 162. The drain hole 168 is formed in
the pressure control chamber 160 such that the oil filled in the
lower part of the plunger 162 is discharged therethrough.
[0045] The oil filled in the lower part of the plunger 162 dampens
the plunger 162 to provide smooth movement. However, when a vehicle
does not run with the oil filled in the lower part of the plunger
162 for a long time, the oil is discharged to the bypass passage
140 through the drain hole 168 to thereby remove an internal
damping operation. Under this situation in a case where pressure is
applied to the plunger 162 due to the discharging pressure of oil
when starting the vehicle, noise and vibration may be
generated.
[0046] In order to solve this problem according to an embodiment of
the present inventive concept, as shown in FIG. 3, a baffle 142
formed in the pressure control chamber 160 extends from the bypass
passage toward one side of the drain hole 168.
[0047] The baffle 142 extends upward from the one side of the drain
hole 168 which is formed in the pressure control chamber 160 on the
bypass passage 140 to form a filling flow passage 144 together with
an inner wall of the pump housing 100. Here, The oil pump cover to
be connected to a side surface of the pump housing 100 has a
protruded section to be contacted with a flat surface of the baffle
142 when assembled, such that the filling flow passage 144 is
formed with the baffle 142, the inner wall 106 of the pump housing
100 and the protruded section of the oil pump cover, when the oil
pump is fully assembled.
[0048] That is, according to an embodiment of the present
disclosure, the baffle 142 extends to one side of the drain hole
168 on the bypass passage 140 to form the filling flow passage 144
such that oil is discharged through the drain hole 168 of the
pressure control chamber 160, not to flow to the bypass passage
140, but to remain in the filling flow passage 144, thereby keeping
the oil filled in the lower part of the plunger 162.
[0049] As described above, the oil is kept in the pressure control
chamber 160 through the filling flow passage 144 formed by the
baffle 142 so that even when a vehicle is stationary with the oil
filled in the pressure control chamber 160 for a long time, since
the oil is kept in the lower part of the plunger 162, the plunger
162 can be dampened with the oil when the engine starts running, to
prevent resonance, thereby improving NVH performance.
[0050] The baffle 142 extends upwardly from the inner wall 106 of
the pump housing 100 to form the filling flow passage 144 including
the drain hole 168 wherein the drain hole 168 is disposed at the
lowest side of the filling flow passage 144.
[0051] That is, the drain hole 168 formed in the pressure control
chamber 160 is disposed at the lowest side of the filling flow
passage 144 formed by the baffle 142 so that a sufficient amount of
oil flow remained in the filling flow passage 144 can be ensured.
Further, the oil discharged through the drain hole 168 moves
upwardly from the lowest side of the filling flow passage 144 and
then flows to the bypass passage 140, thereby continuously
circulating oil through the filling flow passage 144.
[0052] FIG. 5 is a view showing differences in generations of noise
and pressure between a conventional oil pump of an engine and an
oil pump of an engine of the present inventive concept as described
above, when staring the vehicle.
[0053] According to a conventional oil pump, it is shown that when
the engine starts while the oil in the lower part of the plunger
162 of the pressure control chamber 160 leaks out in a vehicle is
left stationary for a long time, pressure variation of oil is great
as 1-3 bar due to resonance as a damping effect with oil is
removed. As a result, surging noise is generated at frequencies of
300-400 Hz and 600-800 Hz.
[0054] However, according to an embodiment of the present inventive
concept, it is shown that the oil is maintained at a lower part of
the plunger 162 of the pressure control chamber 160, and thus, the
damping effect of the oil is maintained so that the pressure
variation of oil is reduced greatly to 0.5 bar when the engine
starts, and further the noise generation is resolved, thereby
improving NVH performance.
[0055] According to the oil pump configured as described above, the
amount of oil flow that is bypassed through the bypass hole
gradually increases by controlling oil pressure, thereby minimizing
generation of pressure variation due to the excessive amount of oil
flow.
[0056] Furthermore, according to the oil pump of the present
inventive concept, oil is ensured at a predetermined level through
the filling flow passage formed by the baffle so that the d oil
serves to dampen the plunger even when a vehicle is stopped for a
long time, thereby reducing resonance.
[0057] The invention has been described in detail with reference to
exemplary embodiments thereof. However, it will be appreciated by
those skilled in the art that changes may be made in these
embodiments without departing from the principles and spirit of the
invention, the scope of which is defined in the appended claims and
their equivalents.
* * * * *